JPH08225611A - Production of solid catalyst component for polymerization of olefin - Google Patents

Abstract

PURPOSE: To produce a solid catalyst component which, when used in the polymerization of olefins, can act with such a high activity that the deashing step can be dispensed with, gives a very high yield of a highly stereoregular polymer and excellent continuing property in catalytic acitivity, and can give a polymer of a high bulk density. CONSTITUTION: A suspension composition obtained by suspending a dialkoxymagnesium (a) in a normally liquid aromatic hydrocarbon (b) and bringing the obtained suspension into contact with a titanium halide compound (c) is washed with component (b) and brought into contact with component (c). In some step of this process, the mixture is brought into contact with a phthalic diester.

Description

Detailed Description of the Invention

[0001]

[0001] The present invention relates to a process for producing a high-performance solid catalyst component capable of acting highly active when olefins are polymerized and capable of obtaining a stereoregular polymer in an extremely high yield. More specifically, dialkoxymagnesium is suspended in a liquid aromatic hydrocarbon at room temperature,
Thereafter, the suspension-shaped composition obtained by contacting with titanium halide is washed with the aromatic hydrocarbon and then further contacted with the titanium halide, at which time, contact with a diester of phthalic acid is performed. The present invention relates to a method for producing a solid catalyst component for olefin polymerization, which comprises:

[0002]

2. Description of the Related Art Conventionally, a combination of a titanium halide as a catalyst component and an organoaluminum compound has been widely used as a catalyst for the polymerization of olefins. Since the yield of the polymer (hereinafter, referred to as polymerization activity per catalyst component and titanium in the catalyst component) is low, a so-called deashing step for removing catalyst residues was inevitable. Since this deashing process uses a large amount of alcohol or a chelating agent, a recovery device or a regenerating device for them is indispensable, and resources,
There were many problems such as energy and other incidents, and it was an important issue that a person skilled in the art would need to solve immediately. Numerous studies have been made and proposed to increase the polymerization activity of the catalyst component, particularly titanium in the catalyst component, in order to eliminate this complicated deashing step.

[0003] In particular, a recent tendency is that a transition metal compound such as a titanium halide as an active ingredient is supported on a supporting substance such as magnesium chloride, so that when used for polymerization of olefins, the titanium content in the catalyst component is reduced. Many techniques have been found to increase the polymerization activity of the polymer. For example, in Japanese Patent Application Laid-Open No. 50-126590, magnesium chloride as a carrier substance is brought into contact with an aromatic monocarboxylic acid diester by mechanical means, and a titanium tetrahalide is brought into contact with the obtained solid composition in a liquid phase. A method for obtaining a catalyst component by dissolving the catalyst component is disclosed.

However, chlorine contained in magnesium chloride, which is the mainstream of the carrier substance, deteriorates the produced polymer in the same manner as the halogen element in the titanium halide,
Not only causes yellowing, but also causes corrosion of equipment used in processes such as granulation and molding. Therefore, high activity is required so that the effect of chlorine can be practically ignored.
In the catalysts using a catalyst component using magnesium chloride as a carrier substance disclosed in the above-mentioned publications, there has not been obtained a catalyst exhibiting sufficient performance up to the present.

Further, in a catalyst using a catalyst component using magnesium chloride as a carrier or a so-called highly active supported catalyst which has recently been variously proposed, the polymerization activity per unit time is high in the early stage of the polymerization, but the polymerization activity is high. The decrease with the passage of time is large, causing a problem in the process operation. In addition, when a longer polymerization time such as block copolymerization is required, it has been practically impossible to use.

It is generally required that these catalysts coexist with an aromatic monocarboxylic acid ester at the time of polymerization. In this case, the amount of the aromatic monocarboxylic acid ester used depends on the amount of the ester used in preparing the catalyst component. Since the amount is large as compared with the above, there is a drawback that an ester odor peculiar to the produced polymer is imparted. Means for Solving the Problems The present inventors have solved the above-mentioned problems, and have previously provided a catalyst using dialkoxymagnesium as a starting material, which has high polymerization activity, excellent sustainability, and no ester odor. Kaisho 60
-44507).

[0007]

However, although the polymerization activity and the sustainability thereof have been tentatively achieved,
Properties such as stereoregularity and bulk specific gravity are not sufficient, and this is a major problem particularly in the production of polyolefins on an industrial scale, and the improvement has been a strong demand from the deceptive world. Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the problems of the prior art, and have reached the present invention and propose the present invention.

[0008]

Means for Solving the Problems That is, the present invention provides (a)
The dialkoxymagnesium is (b) suspended in an aromatic hydrocarbon liquid at room temperature, and then (c)
After washing the suspension composition obtained by contacting a titanium halide represented by X ₄ (wherein X is a halogen element) with the component (b), the component (c) is further contacted. At this time, the present invention provides a method for producing a solid catalyst component for olefin polymerization, which comprises contacting (d) a diester of phthalic acid at any point. Hereinafter, the present invention will be described in detail.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The dialkoxymagnesium used in the present invention includes diethoxymagnesium, diptoxymagnesium, diphenoxymagnesium, dipropoxymagnesium, di-sec-butoxymagnesium, di-tert-butoxymagnesium, and the like.
Examples thereof include di-iso-propoxy magnesium, and among them, diethoxy magnesium and dipropoxy magnesium are preferable.

Examples of the aromatic hydrocarbon which is liquid at normal temperature used in the present invention include toluene, xylene, benzene, ethylbenzene, propylbenzene and trimethylbenzene. Examples of the phthalic acid diester used in the present invention include dimethyl phthalate, diethyl phthalate, di-n-propyl phthalate, di-iso-propyl phthalate, di-n-butyl phthalate, di-iso-butyl phthalate, and diamyl phthalate. , Di-iso-amyl phthalate, n-butylethyl phthalate, iso-butylethyl phthalate, ethyl-n-propyl phthalate and the like.

The general formula TiX ₄ used in the present invention
(Wherein X is a halogen element) TiCl ₄ , TiBr ₄ , TiI _{4, and the} like are given as examples of the titanium halide (hereinafter, simply referred to as “titanium halide”). Of these, TiCl ₄ is preferable. Used.

In the present invention, the use ratio of each raw material is arbitrary as long as it does not adversely affect the performance of the produced catalyst component, and is not particularly limited, but usually 1 g of dialkoxymagnesium is used, Phthalic acid diester is in the range of 0.01 to 2 g, preferably 0.1 to 1 g, and titanium halide is in the range of 0.1 g or more, preferably 1 g or more. Further, the aromatic hydrocarbon which is liquid at ordinary temperature is used in an arbitrary ratio, but is preferably an amount capable of forming a suspension.

In the present invention, the suspension of dialkoxymagnesium in the aromatic hydrocarbon is carried out at room temperature to a temperature lower than the boiling point of the aromatic hydrocarbon which is usually used for 100 hours or less, preferably 10 hours or less. At this time, it is necessary that the suspension does not become a uniform solution. The suspension is contacted with a titanium halide and the composition in suspension obtained by the contact is usually from -20 ° C to the boiling point of the titanium halide used, preferably from 50 to 120 ° C. At a temperature of 10 minutes to 10 hours.

Before the second contact with the titanium halide, the above-mentioned suspension composition is washed with an aromatic hydrocarbon which is liquid at room temperature, preferably at a temperature of 50 ° C. or higher. It is lower than the boiling point of the aromatic hydrocarbon, and the amount of the aromatic hydrocarbon used and the number of washings are 1 or more, and at least 1 or more in terms of volume ratio to the suspension. The means for contacting each component is not particularly limited as long as it can contact each component sufficiently, but it is usually carried out while stirring using a container equipped with a stirrer.

The titanium halide in the present invention can be diluted with the aromatic hydrocarbon and used.
The produced solid catalyst component can be washed with an inert organic solvent such as n-heptane. The solid contact component of the present invention produced as described above is combined with a silicon compound as an external electron donating compound and an organoaluminum compound as an organometallic catalyst component to form an olefin polymerization catalyst.

The silicon compound used is represented by the general formula SiR _m (OR ') _4-m (wherein R is hydrogen, an alkyl group, a cycloalkyl group or an aryl group, and R' is an alkyl group or an aryl group. And m is 0 ≦ m ≦ 4). Examples of the phenylalkoxysilane include phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, and phenyltrisilane. Isopropoxy silane, diphenyl dimethoxy silane, diphenyl diethoxy silane, etc., and examples of alkylalkoxy silanes are tetramethoxy silane, tetraethoxy silane, trimethoxy ethyl silane, trimethoxy methyl silane, triethoxy methyl silane, ethyl triethoxy sila And ethyltriisopropoxysilane. The solid catalyst component of the present invention can be used for polymerization of olefins in combination with other external electron donating compounds other than those described above.

On the other hand, the organoaluminum compound has the general formula R
_n AlX _3-n (wherein R is an alkyl group having 1 to 4 carbon atoms, X is any of hydrogen, chlorine, bromine and iodine, and n is 0 <
n ≦ 3. ), Specifically, triethylaluminum, diethylaluminum chloride, tri-aluminum
Iso-butylaluminum, diethylaluminum bromide, diethylaluminum hydride and the like can be mentioned, and among them, triethylaluminum is preferably used.

The organoaluminum compound used is used in a molar ratio of 1 to 1000 per mol of titanium atoms in the catalyst component, and the silicon compound is 1 or less, preferably 1 or less, per mol of the organoaluminum compound. 0.00
It is used in the range of 5 to 0.5. The polymerization can be carried out in the presence or absence of an organic solvent, and the olefin monomer can be used in either a gas or liquid state. The polymerization temperature is 200 ° C. or lower, preferably 100 ° C. or lower, and the polymerization pressure is 100 kg / cm ² · G or lower, preferably 50 kg / cm ² · G or lower. Olefins homopolymerized or copolymerized using the solid catalyst component produced by the method of the present invention are ethylene, propylene,
1-butene, 4-methyl-1-pentene and the like.

[0019]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples. Example 1 (1) Preparation of solid catalyst component: A 200 ml round-bottomed flask sufficiently purged with nitrogen gas and equipped with a stirrer was charged with 10 g of diethoxymagnesium and 80 ml of toluene to form a suspended state. TiCl ₄ 2 is added to this suspension.
0 ml was added, the temperature was raised to 90 ° C., and 2.7 ml of di-n-butyl phthalate was added. The temperature was further raised, and the mixture was reacted at 115 ° C. for 2 hours with stirring. After the completion of the reaction, toluene 1 at 90 ° C.
After washing twice with 00 ml, fresh 80 ml of toluene and TiCl
₄ 20 ml was added and reacted at 115 ° C. with stirring for 2 hours. After completion of the reaction, the solid catalyst component was obtained by washing 10 times with 200 ml of 40 ° C. n-heptane. The titanium content in this solid catalyst component was 2.61% by weight.

(2) Polymerization; 700 ml of n-heptane was charged into an autoclave equipped with a stirrer and having an inner volume of 2.01 which was completely replaced with nitrogen gas, and 301 mg of triethylaluminum and phenyltriethoxysilane were maintained while maintaining a nitrogen gas atmosphere. 64 mg, and then 0.2 mg of the solid catalyst component as titanium atoms were charged. Thereafter, 150 ml of hydrogen gas was charged, and the temperature was raised to 70 ° C. and 6 kg while introducing propylene gas.
Polymerization was carried out for 4 hours while maintaining the pressure of / cm ² · G.
After the polymerization was completed, the solid polymer obtained was filtered, heated to 80 ° C. and dried under reduced pressure. On the other hand, the amount of the polymer dissolved in the polymerization solvent by condensing the filtrate is (A) and the amount of the solid polymer is (B). Also, the obtained solid polymer was heated to 6 with boiling n-heptane.
After time extraction, a polymer insoluble in n-heptane was obtained. This amount is defined as (C).

The polymerization activity (D) per catalyst component is represented by formula (1).

[Equation 1]

The yield (E) of the crystalline polymer is represented by the formula (2).

[Equation 2]

The yield (F) of the whole crystalline polymer was determined by the formula (3).

(Equation 3) In addition, the residual chlorine in the produced polymer (G), M of the produced polymer
I is represented by (H) and bulk specific gravity is represented by (I). The results obtained are shown in Table 1.
It was as shown in.

Example 2 The procedure was as described in Example 1, except that the polymerization time was 6 hours. The obtained results are as shown in Table 1.

Example 3 The procedure was as described in Example 1, except that 60 ml of toluene and 40 ml of TiCl ₄ were used. At this time, the titanium content in the solid catalyst component was 2.69% by weight. The obtained results are as shown in Table 1.

Example 4 The procedure of Example 1 was repeated except that 2.4 ml of di-n-propyl phthalate was used instead of di-n-butyl phthalate. At this time, the titanium content in the solid catalyst component was 2.74% by weight. The obtained results are as shown in Table 1.

[0027]

[Comparative example]

Comparative Example 1 (1) Preparation of solid catalyst component A capacity of 20 which was sufficiently replaced with nitrogen gas and equipped with a stirrer
A 0 ml round bottom flask was charged with 5 g of diethoxymagnesium, 1.2 g of di-n-propyl phthalate and 50 ml of methylene chloride to form a suspension, and the mixture was stirred under reflux for 1 hour. The suspension is then poured into a 500 ml volume equipped with a stirrer.
Was pumped into 200 ml of room temperature TiCl ₄ in a round-bottomed flask, heated to 90 ° C., and reacted with stirring for 2 hours.
After completion of the reaction, it was washed 10 times with 200 ml of n-heptane at 40 ° C., 200 ml of TiCl ₄ was newly added, and the reaction was carried out at 90 ° C. for 2 hours with stirring. After completion of the reaction, the reaction mixture was cooled to 40 ° C., and then washed repeatedly with 200 ml of n-heptane. When chlorine was no longer detected in the washing solution, washing was completed to obtain a solid catalyst component. The titanium content in the solid catalyst component was 3.64% by weight.

(2) Polymerization Polymerization was carried out according to the method described in Example 1, except that 0.3 mg of the solid catalyst component was used as a titanium atom. The results obtained are as shown in Table 1.

[0029]

[Table 1]

[0030]

When the olefins are polymerized using the solid catalyst component obtained by the method of the present invention, the resulting polymer has extremely high stereoregularity. In addition, the extremely high activity of the catalyst makes it possible to keep the catalyst residue in the produced polymer extremely low, and the amount of residual chlorine is so small that the depolymerization step is not required at all. Effect of chlorine on water can be reduced.

Chlorine contained in the produced polymer causes corrosion of equipment used in processes such as granulation and molding, and also causes deterioration and yellowing of the produced polymer itself. This is extremely important in terms of process and product quality. Furthermore, the present invention improves the essential drawbacks of so-called highly active supported catalysts, in which the activity per unit time of the catalyst is greatly reduced with the course of polymerization, and is not only applied to homopolymerization but also to copolymerization. It is intended to provide a practically applicable catalyst.

Further, in the industrial production of polyolefin, the bulk specific gravity of the produced polymer becomes a very serious problem in view of the effective capacity of the polymerization apparatus and the efficiency of the post-treatment process. When olefins are polymerized using a solid catalyst component, the bulk density of the resulting polymer is extremely high, and its outstanding performance is remarkably exhibited.

Conventionally, in the industrial production of olefin polymers, coexistence of hydrogen at the time of polymerization has been generally considered from the viewpoint of MI control and the like, but a catalyst using the above-mentioned catalyst component having magnesium chloride as a carrier. Had a drawback that its activity and stereoregularity were significantly reduced in the presence of hydrogen. However, when olefins are polymerized in the presence of hydrogen using the catalyst obtained according to the present invention, even when the MI of the produced polymer is extremely high, the activity and stereoregularity hardly decrease, and such an effect is obtained. Is a huge benefit to the industry.

[Brief description of drawings]

FIG. 1 shows a flow sheet of a manufacturing method according to the present invention.

Claims (1)

[Claims] 1. (a) dialkoxymagnesium,
(B) Suspending in a liquid aromatic hydrocarbon at room temperature, and then contacting (c) a titanium halide represented by the general formula TiX ₄ (where X is a halogen element),
The obtained suspension composition is washed with the component (b), and then brought into contact with the component (c).
(D) A method for producing a solid catalyst component for olefin polymerization, which is brought into contact with a diester of phthalic acid.